A pair of suicide bombers killed 22 people while targeting a top army officer in southwest Pakistan on Wednesday, missing him and killing his wife, several guards, a senior officer and two children, officials said.
Police said they were investigating whether the strike in the city of Quetta was revenge for the recent arrests there of three top al-Qaida suspects, an operation assisted by the CIA.
The Taliban claimed responsibility for the attack, but a spokesman for the group did not mention the arrests.
Instead, he said Brig. Khurram Shahzad, the deputy head of the region's Frontier Corps, was targeted because of an incident several months ago that left five people dead at a checkpoint in the city.
In Wednesday's blasts, the first attacker detonated his vehicle next to a group of Frontier Corps officers close to Shahzad's house. Hurling grenades, the second attacker then stormed the house and blew himself up inside, police officer Naseer Ahmed Kurd said.
Police officer Hamid Shakil said at least 23 people were killed and more than 80 were injured, some critically.
An unidentified 5-year-old girl who security personnel had carried from the scene, bloodied, some of her clothes torn from her body, later died at a government hospital, according to doctor Mohammed Jafar Kakar.
The child was in a rickshaw, with her parents who also died in the attack, he said. Another child was also killed in the blast, along with a colonel in the corps.
Shakil said one of the suicide bombers was carrying an identity card showing him to be a 21-year-old Afghan refugee.
The bombing followed Monday's disclosure of the arrests of the three al-Qaida suspects in Quetta. The Pakistan army statement announcing it stressed the level of CIA involvement _ a possible sign of an upswing in cooperation between two uneasy anti-terror allies after the rancor surrounding the killing of Osama bin Laden in a unilateral U.S. operation.
American officials praised the arrest operation, saying the detention of the most senior militant _ Younis al-Mauritani _ was a significant achievement. The Frontier Corps took part.
"This attack was maybe in reaction to the recent arrests, but we are investigating," police officer Shakil said of the Wednesday blasts.
Islamist militants are seeking to topple Pakistan's Western-allied leaders.
Allied to the insurgents fighting U.S. forces across the border in Afghanistan, the militants have attacked hundreds of government, police, army and civilian targets since 2007, when the violence began in earnest. Many thousands have been killed, and Pakistani authorities have struggled to counter the threat.
Quetta is a dangerous city, thought to be home to al-Qaida and Taliban leaders. It lies close to the border with southern Afghanistan, the heart of the insurgency in that country. It is also wracked by separatist violence, but those rebels have not tended to deploy suicide bombers.
Pakistan didn't say when al-Mauritani and the two other al-Qaida operatives were arrested. But a U.S. official, speaking on condition of anonymity to discuss intelligence matters, has said the arrests took place in the past two weeks.
The unusual announcement about the cooperation between the CIA and Pakistan's Inter-Services Intelligence agency appeared aimed at reversing the widespread perception that ties were badly damaged by bin Laden's killing.
The Pakistanis accused the Americans of violating their sovereignty with the bin Laden raid, while Washington was angry the terror leader was found in a house in a military garrison town in Pakistan.
U.S. Defense Secretary Leon Panetta on Tuesday praised Pakistan for al-Mauritani's arrest.
"It's a tribute to the Pakistanis, who worked with us on this effort to be able to go after him," Panetta told reporters, adding that he assumes the U.S. will ask the Pakistani authorities for permission to interrogate him.
AP National Security Writer Robert Burns contributed to this report.